The pressure at the center of the earth is probably greater than 3x106 atm, and the temperature there is about 4000 °C. What is the change in the Gibbs function of reaction on going from crust to core for a reaction in which  Vm = 1 cm3 mol-1 and  Sm = 2.1 J K-1 mol-1

The change in the Gibbs function of reaction on going from crust to core, dG=291442.4 J/mol

Explanation:

dG=vdp-sdT

Where T is the temperature.

P is the pressure.

S is entropy

V = 1cm3 = 10-6 m3

P = 3*10∧6 atm = 3*10∧11 pa

The temperature at the center of the earth, Tc = 4*103 °C. : The temperature at the sufrace (crust) of the earth, Ts = 298K.

Subistuting the values

dG = (10-6 * (3*1011-105) - (2.1 (4373-298))

dG=291442.4 J/mol.